The layer transfer process is one of the most promising methods for low-cost and highly-efficient solar cells, in which transferrable mono-crystalline silicon thin wafers or films can be produced directly from gaseous...The layer transfer process is one of the most promising methods for low-cost and highly-efficient solar cells, in which transferrable mono-crystalline silicon thin wafers or films can be produced directly from gaseous feed-stocks. In this work, we show an approach to preparing seeded substrates for layer-transferrable silicon films. The commercial silicon wafers are used as mother substrates, on which periodically patterned silicon rod arrays are fabricated, and all of the surfaces of the wafers and rods are sheathed by thermal silicon oxide. Thermal evaporated aluminum film is used to fill the gaps between the rods and as the stiff mask, while polymethyl methacrylate （PMMA） and photoresist are used as the soft mask to seal the gap between the filled aluminum and the rods. Under the joint resist of the stiff and soft masks, the oxide on the rod head is selectively removed by wet etching and the seed site is formed on the rod head. The seeded substrate is obtained after the removal of the masks. This joint mask technique will promote the endeavor of the exploration of mechanically stable, unlimitedly reusable substrates for the kerfless technology.展开更多
Chinese milk vetch(Astragalussinicus L.)is an environment-friendly green manure used for rice with low carbon/nitrogen(C/N)ratio and high moisture.To improve the added values of milk vetch,the feasibility of co-compos...Chinese milk vetch(Astragalussinicus L.)is an environment-friendly green manure used for rice with low carbon/nitrogen(C/N)ratio and high moisture.To improve the added values of milk vetch,the feasibility of co-composting of milk vetch with rice straw was evaluated.The probability of using the milk vetch-based compost as a peat substitute in seeding substrate of vegetable was further tested.The changes in physicochemical properties during co-composting of milk vetch and rice straw were evaluated,depending on three treatments:(1)milk vetch alone(MV),(2)co-composting of milk vetch and rice straws with 4:1 ration(w/w)(MV+S)and(3)MV+S with the addition of 3%(w/w)microbial inoculation(MV+S+M).The entire composting durations were 15 d,24 d,and 24 d in MV,MV+S,MV+S+M composts.Compare to MV compost,both the MV+S,MV+S+M composts increased the temperature,pH,organic C,total nitrogen(N),total potassium(K)and the germination index(GI)(over 100)during the cooling/mature phase,and decreased total N loss,and generally,the improvements or reductions were greater in the MV+S+M compost than in the MV+S compost.Additionally,the MV+S+M compost was added at a peat substitute rates of 0%,20%,40%,80%and 100%in a pot experiment to testify the utilization of milk vetch-based compost in substrates.The results showed that the substrate with 40%substitute rate increased the cabbage seeding growth,and that the electrical conductivity was the limiting factor of preventing the substitute rate increase.Another pot experiment demonstrated that the substrate with 40%peat substitute increased the cucumber growth as compared to the substrate without compost.In conclusion,the co-composting milk vetch with rice straw was feasible and quick,and microbial inoculation accelerated the composting process and improved the compost quality.The milk vetch-based composts were nutrient-rich and safe,and thus,can replace part of peat in vegetable seeding substrate.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11374313)the Young Scientists Fund of the National Natural Science Foundation of China(Grant No.11504392)
文摘The layer transfer process is one of the most promising methods for low-cost and highly-efficient solar cells, in which transferrable mono-crystalline silicon thin wafers or films can be produced directly from gaseous feed-stocks. In this work, we show an approach to preparing seeded substrates for layer-transferrable silicon films. The commercial silicon wafers are used as mother substrates, on which periodically patterned silicon rod arrays are fabricated, and all of the surfaces of the wafers and rods are sheathed by thermal silicon oxide. Thermal evaporated aluminum film is used to fill the gaps between the rods and as the stiff mask, while polymethyl methacrylate （PMMA） and photoresist are used as the soft mask to seal the gap between the filled aluminum and the rods. Under the joint resist of the stiff and soft masks, the oxide on the rod head is selectively removed by wet etching and the seed site is formed on the rod head. The seeded substrate is obtained after the removal of the masks. This joint mask technique will promote the endeavor of the exploration of mechanically stable, unlimitedly reusable substrates for the kerfless technology.
基金This work was supported by the National Natural Science Foundation of China(Grant No.31870501)Scientific and Technological Achievements Cultivation Project of Hubei Academy of Agricultural Sciences(Grant No.2017CGPY01)the Open Project of Key Laboratory of Fertilization from Agricultural Wastes(Grant No.KLFAW201705).
文摘Chinese milk vetch(Astragalussinicus L.)is an environment-friendly green manure used for rice with low carbon/nitrogen(C/N)ratio and high moisture.To improve the added values of milk vetch,the feasibility of co-composting of milk vetch with rice straw was evaluated.The probability of using the milk vetch-based compost as a peat substitute in seeding substrate of vegetable was further tested.The changes in physicochemical properties during co-composting of milk vetch and rice straw were evaluated,depending on three treatments:(1)milk vetch alone(MV),(2)co-composting of milk vetch and rice straws with 4:1 ration(w/w)(MV+S)and(3)MV+S with the addition of 3%(w/w)microbial inoculation(MV+S+M).The entire composting durations were 15 d,24 d,and 24 d in MV,MV+S,MV+S+M composts.Compare to MV compost,both the MV+S,MV+S+M composts increased the temperature,pH,organic C,total nitrogen(N),total potassium(K)and the germination index(GI)(over 100)during the cooling/mature phase,and decreased total N loss,and generally,the improvements or reductions were greater in the MV+S+M compost than in the MV+S compost.Additionally,the MV+S+M compost was added at a peat substitute rates of 0%,20%,40%,80%and 100%in a pot experiment to testify the utilization of milk vetch-based compost in substrates.The results showed that the substrate with 40%substitute rate increased the cabbage seeding growth,and that the electrical conductivity was the limiting factor of preventing the substitute rate increase.Another pot experiment demonstrated that the substrate with 40%peat substitute increased the cucumber growth as compared to the substrate without compost.In conclusion,the co-composting milk vetch with rice straw was feasible and quick,and microbial inoculation accelerated the composting process and improved the compost quality.The milk vetch-based composts were nutrient-rich and safe,and thus,can replace part of peat in vegetable seeding substrate.
